From d35d3a5820b0db4c7d69a4fcd8c0191e75c0829c Mon Sep 17 00:00:00 2001
From: Keyi Xie <xiekeyi98@gmail.com>
Date: Thu, 7 Mar 2019 16:36:11 +0800
Subject: [PATCH] variable: change "ddl_slow_threshold" (#9043)

---
 executor/set_test.go             |  7 +++++++
 sessionctx/variable/session.go   |  2 ++
 sessionctx/variable/sysvar.go    |  1 +
 sessionctx/variable/tidb_vars.go | 14 +++++++++-----
 sessionctx/variable/varsutil.go  |  2 ++
 5 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/executor/set_test.go b/executor/set_test.go
index afface4eb3908..6fdb59fef08ab 100644
--- a/executor/set_test.go
+++ b/executor/set_test.go
@@ -138,6 +138,13 @@ func (s *testSuite2) TestSetVar(c *C) {
 	tk.MustExec("set character_set_results = NULL")
 	tk.MustQuery("select @@character_set_results").Check(testkit.Rows(""))
 
+	tk.MustExec("set @@session.ddl_slow_threshold=12345")
+	tk.MustQuery("select @@session.ddl_slow_threshold").Check(testkit.Rows("12345"))
+	c.Assert(variable.DDLSlowOprThreshold, Equals, uint32(12345))
+	tk.MustExec("set session ddl_slow_threshold=\"54321\"")
+	tk.MustQuery("show variables like 'ddl_slow_threshold'").Check(testkit.Rows("ddl_slow_threshold 54321"))
+	c.Assert(variable.DDLSlowOprThreshold, Equals, uint32(54321))
+
 	// Test set transaction isolation level, which is equivalent to setting variable "tx_isolation".
 	tk.MustExec("SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED")
 	tk.MustQuery("select @@session.tx_isolation").Check(testkit.Rows("READ-COMMITTED"))
diff --git a/sessionctx/variable/session.go b/sessionctx/variable/session.go
index 15f350d2160b6..816b3e327694b 100644
--- a/sessionctx/variable/session.go
+++ b/sessionctx/variable/session.go
@@ -667,6 +667,8 @@ func (s *SessionVars) SetSystemVar(name string, val string) error {
 		atomic.StoreUint32(&ProcessGeneralLog, uint32(tidbOptPositiveInt32(val, DefTiDBGeneralLog)))
 	case TiDBSlowLogThreshold:
 		atomic.StoreUint64(&config.GetGlobalConfig().Log.SlowThreshold, uint64(tidbOptInt64(val, logutil.DefaultSlowThreshold)))
+	case TiDBDDLSlowOprThreshold:
+		atomic.StoreUint32(&DDLSlowOprThreshold, uint32(tidbOptPositiveInt32(val, DefTiDBDDLSlowOprThreshold)))
 	case TiDBQueryLogMaxLen:
 		atomic.StoreUint64(&config.GetGlobalConfig().Log.QueryLogMaxLen, uint64(tidbOptInt64(val, logutil.DefaultQueryLogMaxLen)))
 	case TiDBRetryLimit:
diff --git a/sessionctx/variable/sysvar.go b/sessionctx/variable/sysvar.go
index fd454c1b52334..ecbad582c5014 100644
--- a/sessionctx/variable/sysvar.go
+++ b/sessionctx/variable/sysvar.go
@@ -675,6 +675,7 @@ var defaultSysVars = []*SysVar{
 	/* The following variable is defined as session scope but is actually server scope. */
 	{ScopeSession, TiDBGeneralLog, strconv.Itoa(DefTiDBGeneralLog)},
 	{ScopeSession, TiDBSlowLogThreshold, strconv.Itoa(logutil.DefaultSlowThreshold)},
+	{ScopeSession, TiDBDDLSlowOprThreshold, strconv.Itoa(DefTiDBDDLSlowOprThreshold)},
 	{ScopeSession, TiDBQueryLogMaxLen, strconv.Itoa(logutil.DefaultQueryLogMaxLen)},
 	{ScopeSession, TiDBConfig, ""},
 	{ScopeGlobal, TiDBDDLReorgWorkerCount, strconv.Itoa(DefTiDBDDLReorgWorkerCount)},
diff --git a/sessionctx/variable/tidb_vars.go b/sessionctx/variable/tidb_vars.go
index e0eeb79a3a5d4..b6d98ea282c6c 100644
--- a/sessionctx/variable/tidb_vars.go
+++ b/sessionctx/variable/tidb_vars.go
@@ -34,6 +34,8 @@ import (
 
 // TiDB system variable names that only in session scope.
 const (
+	TiDBDDLSlowOprThreshold = "ddl_slow_threshold"
+
 	// tidb_snapshot is used for reading history data, the default value is empty string.
 	// The value can be a datetime string like '2017-11-11 20:20:20' or a tso string. When this variable is set, the session reads history data of that time.
 	TiDBSnapshot = "tidb_snapshot"
@@ -285,6 +287,7 @@ const (
 	DefTiDBForcePriority             = mysql.NoPriority
 	DefTiDBUseRadixJoin              = false
 	DefEnableWindowFunction          = false
+	DefTiDBDDLSlowOprThreshold       = 300
 )
 
 // Process global variables.
@@ -295,9 +298,10 @@ var (
 	ddlReorgBatchSize      int32 = DefTiDBDDLReorgBatchSize
 	ddlErrorCountlimit     int64 = DefTiDBDDLErrorCountLimit
 	// Export for testing.
-	MaxDDLReorgBatchSize int32  = 10240
-	MinDDLReorgBatchSize int32  = 32
-	DDLSlowOprThreshold  uint32 = 300 // DDLSlowOprThreshold is the threshold for ddl slow operations, uint is millisecond.
-	ForcePriority               = int32(DefTiDBForcePriority)
-	ServerHostname, _           = os.Hostname()
+	MaxDDLReorgBatchSize int32 = 10240
+	MinDDLReorgBatchSize int32 = 32
+	// DDLSlowOprThreshold is the threshold for ddl slow operations, uint is millisecond.
+	DDLSlowOprThreshold uint32 = DefTiDBDDLSlowOprThreshold
+	ForcePriority              = int32(DefTiDBForcePriority)
+	ServerHostname, _          = os.Hostname()
 )
diff --git a/sessionctx/variable/varsutil.go b/sessionctx/variable/varsutil.go
index 563681749f54d..db8cce5ba7ed9 100644
--- a/sessionctx/variable/varsutil.go
+++ b/sessionctx/variable/varsutil.go
@@ -114,6 +114,8 @@ func GetSessionOnlySysVars(s *SessionVars, key string) (string, bool, error) {
 		return mysql.Priority2Str[mysql.PriorityEnum(atomic.LoadInt32(&ForcePriority))], true, nil
 	case TiDBSlowLogThreshold:
 		return strconv.FormatUint(atomic.LoadUint64(&config.GetGlobalConfig().Log.SlowThreshold), 10), true, nil
+	case TiDBDDLSlowOprThreshold:
+		return strconv.FormatUint(uint64(atomic.LoadUint32(&DDLSlowOprThreshold)), 10), true, nil
 	case TiDBQueryLogMaxLen:
 		return strconv.FormatUint(atomic.LoadUint64(&config.GetGlobalConfig().Log.QueryLogMaxLen), 10), true, nil
 	case PluginDir: